# US 2021/0280775 A1 · Giant enhancement of spin-orbit torque by interface scattering from ultra-thin insertion layers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0280775 A1 - Document ID: US20210280775A1 - Status: Published application - Kind: A1 - Application number: 16/820,496 - Filed: 2020-03-16 - Published: 2021-09-09 - Earliest claimed: 2019-03-15 - Assignees: Cornell University - Applicants: Cornell University - Inventors: Robert A. BUHRMAN; Lijun ZHU - Web page: https://patentgrep.com/patent/US20210280775A1 ## CPC - H10N 50/10: Magnetoresistive devices - H10N 52/80: Constructional details - H10N 50/85: Materials of the active region - H10N 52/00: Hall-effect devices (integrated devices or assemblies of multiple devices H10N59/00) - H10N: ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR ## Abstract Methods, systems, and devices are disclosed for enhancement of spin-orbit torque. In one aspect, a magnetic device includes a magnetic tunneling junction (MTJ), including a free magnetic layer, a pinned magnetic layer and a non-magnetic junction layer between the free magnetic layer and the pinned magnetic layer, and a spin Hall effect metal layer that includes one or more insertion metal layers operable to introduce interfacial scattering of electrons flowing in the spin Hall metal layer to increase the spin current that interacts with and changes the magnetization of the free magnetic layer of the MTJ. ## Claims ### Claim 1 A magnetic device, comprising: a magnetic tunneling junction (MTJ) that includes (1) a pinned magnetic layer having a fixed magnetization direction, (2) a free magnetic layer having a changeable magnetization direction, and (3) a non-magnetic junction layer between the free magnetic layer and the pinned magnetic layer and formed of an insulator material sufficiently thin to allow tunneling of electrons between the free magnetic layer and the pinned magnetic layer; and a spin Hall effect metal layer including a metal exhibiting a large spin Hall effect to react to a charge current directed into the spin Hall effect metal layer to produce a spin-polarized current that is perpendicular to the charge current, and the spin Hall effect metal layer being parallel to and adjacent to the free magnetic layer to direct the spin-polarized current generated in the spin Hall effect metal layer into the free magnetic layer, wherein the spin Hall effect metal layer includes one or more insertion metal layers structured and operable to introduce interfacial scattering of electrons flowing in the spin Hall metal layer to increase the spin current that interacts with and changes the magnetization of the free magnetic layer of the MTJ. ### Claim 2 (depends on 1) The device as in claim 1, wherein the one or more insertion metal layers include at least one of Hf layer or Ti. ### Claim 3 (depends on 1) The device as in claim 1, wherein the one or more insertion metal layers include a metal that is different from Hf or Ti. ### Claim 4 (depends on 1) The device as in claim 1, wherein the spin Hall effect metal layer includes Pt and the one or more insertion metal layers include Hf layers such that Pt and Hf layers are interleaved. ### Claim 5 (depends on 4) The device as in claim 4, wherein the spin Hall effect metal layer further includes particles to further introduce interfacial scattering of electrons. ### Claim 6 (depends on 5) The device as in claim 5, wherein the particles include MgO particles. ### Claim 7 (depends on 1) The device as in claim 1, wherein the spin Hall effect metal layer includes Pt and the one or more insertion metal layers include Ti layers such that the Pt and Ti layers are interleaved. ### Claim 8 (depends on 7) The device as in claim 7, wherein the spin Hall effect metal layer further includes particles to further introduce interfacial scattering of electrons. ### Claim 9 (depends on 8) The device as in claim 8, wherein the particles include MgO particles. ### Claim 10 (depends on 1) The device as in claim 1, wherein the spin Hall effect metal layer includes Pt and the one or more insertion metal layers include metal layers that are different from Hf and Ti to enhance the scattering of electrons in the Pt such that the Pt and the metal layers are interleaved. ### Claim 11 (depends on 1) The device as in claim 1, wherein the free magnetic layer includes a Co layer or a thin ferromagnetic layer that exhibits a perpendicular magnetic anisotropy (PMA), wherein the interfacial scattering of electrons induced by the one or more insertion metal layers magnifies a spin-orbit torque switching of the Co layer or the thin ferromagnetic layer. ### Claim 12 A magnetic device, comprising: a magnetic spin-orbit torque structure including multi-layer stack of layers structured to include a magnetic layer to exhibit a spin-orbit torque; a spin Hall metal layer coupled to the magnetic layer to produce a charge current in the spin Hall metal layer; and a scattering enhancement layer arranged in the spin Hall metal layer to induce interfacial scattering of electrons within the spin Hall metal layer. ### Claim 13 (depends on 12) The device as in claim 12, wherein the scattering enhancement layer includes at least one of Hf layer or Ti layer. ### Claim 14 (depends on 12) The device as in claim 12, wherein the scattering enhancement layer includes a metal that is different from Hf or Ti. ### Claim 15 (depends on 12) The device as in claim 12, wherein the scattering enhancement layer includes multiple sub-layers such that multiple sub-layers of the spin Hall metal layer and the multiple sub-layers of the scattering enhancement layer are interleaved. ### Claim 16 (depends on 15) The device as in claim 15, wherein the scattering enhancement layer includes a Pt layer and the multiple sub-layers of the scattering enhancement layer includes Hf layers such that Pt and Hf layers are interleaved. ### Claim 17 (depends on 16) The device as in claim 16, wherein the spin Hall metal layer further includes particles dispersed in the spin Hall metal layer to further introduce interfacial scattering of electrons. ### Claim 18 (depends on 17) The device as in claim 17, wherein the particles include MgO molecules. ### Claim 19 (depends on 15) The device as in claim 15, wherein the scattering enhancement layer includes a Pt layer and the multiple sub-layers of the scattering enhancement layer includes Ti layers such that Pt and Ti layers are interleaved. ### Claim 20 (depends on 19) The device as in claim 19, wherein the spin Hall metal layer further includes particles dispersed in the spin Hall metal layer to further introduce interfacial scattering of electrons. ### Claim 21 (depends on 15) The device as in claim 15, wherein the scattering enhancement layer includes a Pt layer and the multiple sub-layers of the scattering enhancement layer includes metal layers that are different from Hf and Ti to enhance the scattering of electrons in the Pt layer such that the Pt layer and the metal layers that are different from Hf and Ti are interleaved. ### Claim 22 (depends on 21) The device as in claim 21, wherein the spin Hall metal layer further includes particles dispersed in the spin Hall metal layer to further introduce interfacial scattering of electrons. ### Claim 23 (depends on 22) The device as in claim 22, wherein the particles include MgO molecules. ### Claim 24 (depends on 12) The device as in claim 12, wherein the scattering enhancement layer includes MgO molecules dispersed in the spin Hall metal layer. ### Claim 25 (depends on 12) The device as in claim 12, wherein the scattering enhancement layer includes a plurality of clusters of MgO molecule dispersed in the spin Hall metal layer.